This invention relates to buoyancy compensators which are used by divers employing self contained underwater breathing apparatus (SCUBA).
A buoyancy compensator is used by divers to adjust their overall specific gravity so that they are either lighter than water so that they can ascend easily, heavier than water so they can descend easily or the same as water (neutrally buoyant) so that they can easily maintain a position in water without ascending or descending.
Buoyancy compensators usually comprise a vest or jacket containing water tight and air tight compartments which can be filled with air to increase buoyancy (to decrease overall specific gravity) or from which air can be released to decrease buoyancy.
Originally such compensators were filled by orally blowing air into the compartments and air was released by opening a valve.
Subsequently such compartments were connected to an air tank (usually breathing air) through a valve such that when the valve was opened air could flow from the tank through a hose into the compensator. Usually another valve attached to the hose could be opened to release air from the compensator to the surrounding environment. In such a case the hose would usually be positioned so that the opening to the environment was closer to the surface of the water than the rest of the compensator which helped to prevent water from entering the compensator through the opening and allowed air to escape even though pressure inside the vest might be equal to exterior pressure. Buoyancy compensators employing an air chamber in the form of a compartmented vest, or otherwise are very well known and for example are described in U.S. Pat. Nos. 3,487,647; 3,727,250; 4,054,132; 4,068,657; 4,523,914; 4,529,333; 4,681,552; 4,779,554; and 4,913,589.
A problem with such known compensators has been a disadvantage in the air release mechanism. In particular the moving of a tube or hose to above the vest before air is released has been inconvenient and cumbersome.
In the event an air release valve were located near the upper shoulder area so that air could be released in most normal body positions, i.e. body horizontal to the water surface or body vertical with head up toward the water surface, opening of the valve was inconvenient due to the location of the valve and operation of such a valve was certainly not conducive to one handed operation with an air supply to the compensator.
U.S. Pat. No. 4,810,134 describes a buoyancy compensator having an air release valve in the shoulder area which is operated by pulling downward (i.e. toward the feet) on a cable secured to the valve. Such pulling is also inconvenient and may in fact distort or move the vest during operation. The cable is not connected to any type of trigger mechanism making operation of both inlet and air release (outlet) valves simple.